Building & home improvement cost guide
Loft Conversion Cost Calculator UK
Estimate loft conversion costs by converted floor area, finish and UK region, with a practical range for early planning. These figures are planning guidance rather than a supplier quotation.
Example for a 30 m² conversion with a standard finish in Norfolk or Suffolk.
Adjust it for your project
JobPrice uses a baseline of £1,750–£2,900 per m², with a minimum project allowance, before regional and finish adjustments.
Calculate my loft conversion costWhat changes the price?
- Dormer, hip-to-gable or rooflight design
- Structural steel and floor strengthening
- Staircase position and headroom
- Bathroom or plumbing additions
- Insulation, fire protection and approvals
Before comparing quotes
- Separate design and approval fees from the build price.
- Confirm structural work and scaffolding are included.
- Check the specification for stairs, windows and insulation.
Compare the same scope, specification and exclusions across every quote. Keep a contingency for changes and hidden conditions.
How to build a reliable loft conversion price
JobPrice uses a baseline of £1,750–£2,900 per m², with a minimum project allowance, before regional and finish adjustments.
Use measured quantities and a written specification, then compare the same inclusions, exclusions and finish level across every contractor quote.
Method note: JobPrice benchmarks are broad planning models, not live supplier quotes. Confirm current local rates, tax, regulation, access and the final specification. Read the full pricing methodology.
How is the loft conversion estimate calculated?
JobPrice uses a baseline of £1,750–£2,900 per m², with a minimum project allowance, before regional and finish adjustments.
Is this loft conversion range a final quote?
No. It is an early planning range. A final quote should use the exact scope, current local rates, applicable tax, access conditions and any legal or professional requirements.
How can I get a more accurate loft conversion price?
Use measured quantities and a written specification, then compare the same inclusions, exclusions and finish level across every contractor quote.